Back to idle and 49C, I disconnected one of the fans. I expected to the see temperatures raise immediately, but that never happened. In stead, it went from 49C to 58C in 10 minutes -- and 58C isn't bad at all with only one fan spinning. But remember all this is on idle.
Time to fire up Genome@home again. This time I got the reaction I was expecting -- the temperatures increased quite fast, passed 60C, passed 70C, passed 75C. By now I was actually getting a little bit nervous, but luckily, it leveled out at 77C. The computer was still acting like normal and I had a sigh of relief. Now imagine this would happen on a single fan heatsink.
Ok, Intel have a throttling mechanism
on their Pentium 4 part that turns down the power of the CPU, cycling it down to idle, but AMD doesn't, or at least not the Thunderbirds. XP's are supposed to have an equivalent feature, but that's a completely different story.
Still, 66C on full load is a bit high, so I decided to try this fan on an AMD XP2200+(Thoroughbred) that I just got, to see if I could even start thinking about overclocking. But alas, my motherboard, the Abit KG7RAID v 1.0, is of course the only version of this board that is not compatible with XP CPUs. I guess the Gods reconed I didn't deserve more luck than that.